Non-unions of the supracondylar area of the humerus are uncommon but they produce profound functional disability. We have successfully treated a series of these non-unions surgically using the Coventry hip screw. This is a large metaphyseal screw which is applied through both humeral condyles and then compressed on to a single 4. 5mm narrow tibial plate applied to the lateral aspect of the humeral shaft. Between 1993 and 2000 we operated on thirteen consecutive patients aged 20 to 81 years (mean age 51 years). All the patients had a severe functional disability. The mean time to surgery was 23 months following their accidents. The average follow up was 16 months (range 8–18 months). All but two of the thirteen patients went on to bony union. The mean time to radiological union was six months (2 to 12 months). The mean arc of flexion doubled to 90 degrees. Until now, the recommended operative technique for stabilisation of non-unions of the distal humerus is identical to that described for primary fracture repair, and involves fixation with two 3. 5 mm plates at 90 degrees. In our experience, this was the technique usually used at the initial operation/s, and is therefore likely to fail again. This correlates with the reported 6–12% non-union rate in the literature. In this series, stable fixation was achieved by using the Coventry hip screw.
Between 1993 and 2000 we treated 14 patients with nonunion of fractures of the distal humerus; 11 had already had previous fixation which had failed. The mean time to surgery was 21 months after injury. All the fractures were very low which made it difficult to obtain a firm hold of the small distal fragment. The problem of fixation was addressed by inserting a Coventry infant hip screw into the humeral condyles. The screw has a thread of wide diameter which gives excellent purchase on the small distal fragment. The condyles can then be compressed on to the humeral shaft using a 4.5 mm narrow tibial dynamic plate. Of these 14 difficult cases of nonunion, 12 progressed to union.
